1. Field of the Invention
The present invention relates to a DC brushless ceiling fan motor. More particularly, the present invention relates to an improvement on the stator and rotor therein.
2. Description of Related Art
In general, a conventional ceiling fan motor has an AC monophase motor design, and the motor stator 40 is made up of a stack of silicon steel laminations 41 formed by a punch machine with an individual thickness of 0.5˜1.0 mm (as shown in FIG. 10). Regarding the process of making such a stator 40, first, every formed silicon steel lamination 41 must be stacked on one another. Second, the rivets are used to secure each silicon steel lamination 41 forming a stacked lamination. Although this kind of method has been used for years, it still has some improvable defects, such as:
1. Poor efficiency: The conventional AC monophase ceiling fan motor uses a shoe box-like electric machinery design. This design type has lower power factors that could result in increased power consumption and electrical inefficiency.
2. High working temperature: As mentioned, due to the lower power factors of the conventional motor design, the efficiency of the motor is lessened. Therefore, after the conventional AC motor has been working at full speed for a short time, the temperature of the inner windings of the motor will rise significantly, up to nearly 100° C. After a short period of use, the insulating materials of the inner motor will wear due to the high temperature and will thus provide less and less insulation over time, further resulting in leakage of electricity and eventually resulting in a short circuit. In addition, because the bearings of the motor have been installed in this high temperature environment, the lubricity of the bearings could also gradually wear off over time. As a result, the bearings will produce a noise due to the abnormal friction, and the loss of lubrication could lead to a lockup of the bearings.
3. Unstable production quality: Instability results from the fact that the stator is made up of a stack of silicon steel laminations 41 and secured by rivets. The two production processes involved in stacking the silicon steel laminations 41 and securing the silicon steel laminations 41 could result in some assembly inaccuracies that influence the stability of the original product measurements. Because of such unpredictable inaccuracies, it is not possible to mass produce these products.
The present invention is intended to improve upon the above mentioned drawbacks of the conventional AC monophase ceiling fan motor. The present invention provides a new stator and rotor design for a DC brushless ceiling fan motor and provides a usage improvement for the materials of the stator and rotor.